D-Glyceraldehyde 3-phosphate dehydrogenase will be studied with various substrates in the presence and absence of acyl phosphate and cyclic AMP inhibitors to ascertain how the cooperative conformational changes brought about by the inhibitors are affecting the activity of the enzyme in terms of the binding of substrates and ease of reaction. Steric effects in the substrate will be studied to obtain unambiguous evidence pertaining to the mechanism of the reactions. Chemical model studies will be undertaken to determine the factors of importance in similar chemical reactions. The hydrolysis and phosphoryl transfer reactions of a series of acyl phosphates will be studied to determine under what conditions phosphoryl transfer to suitable acceptors is most facile.